When most people think about changing the way America uses energy, they imagine new ways of generating electricity like solar farms or new nuclear reactors.

But at an innovation summit organized by the Department of Energy’s high-risk, high-reward research branch, ARPA-E (modeled after Darpa), it’s not just power generation that’s getting a makeover. The companies hawking their ideas there, which all received grant money from ARPA-E or were finalists, are trying to reinvent the entire energy system. Everything is getting a technological re-evaluation from the actual wires that power is transmitted on to the waste heat produced in industrial processes.

And of course there are also new ways of making electricity beyond just burning some rocks or oil to create steam to drive a turbine.

Here are 10 companies that caught our attention. Any one technology is unlikely to solve the looming climate change and peak oil problems, but working together within the larger system, they could tilt the globe away from catastrophe and towards a sustainable future.